Mining operations typically involve blasting and other techniques designed to fragment a rock-mass. Blasting may be necessary to fragment the rock-mass and loosen a resulting muck pile for efficient excavation. Prior to blasting, a geological survey of the rock-mass may be conducted to determine boundaries between high-grade ore, low-grade ore, and waste. However, blasting may cause non-uniform movement of the rock-mass and, consequently, the boundaries between the high-grade ore, low-grade-ore and waste may shift. These shifted boundaries may reduce the accurate delineation between ore and waste regions within the resulting muck pile. As a consequence, ore may cross a previously determined boundary and move into a region designated as waste, where it may be subsequently discarded. Also, dilution of the mined ore can occur when waste material moves across a boundary into an ore region. The ore diluted with waste material may be sent to a concentrator for further processing, which may reduce the efficiency of the ore extraction process. If the movement of the rock-mass following a blast can be accurately tracked, ore loss or dilution may be reduced, increasing mining efficiency and profitability.
Devices and methods have been developed to monitor rock movement caused by blasting. One such device is described in U.S. Patent Publication No. 2005/0012499 (“the '499 publication”), to La Rosa et al, published Jan. 20, 2005. The '499 publication describes a blast movement monitor (BMM) that is placed within a rock-mass. The BMM includes a transmitter for transmitting a signal from the BMM to a detector. Multiple BMMs are placed within the rock-mass and the positions of each BMM are determined before and after the blast. To detect the BMMs, an operator moves across the surface of the blasted rock-mass with a handheld detector. The movement of the rock-mass and boundaries between the ore and waste regions can be approximated by determining the positions of the BMMs before and after the blast.
Although the use of BMMs described in the '499 publication may reduce ore loss or dilution resulting from rock movement following a blast, manual detection of the BMMs may be labor intensive and inefficient as the operator manually moves across the rock-mass, detects the BMMs, and plots BMM movement prior to the excavation process. Further inefficiencies may be created as the work machine operator reads and interprets the plots during the excavation process. Human error may be further increased as the operator may not be provided with an indication of the relative position of the work machine or work tool in relation to the BMMs or plot data.
The boundary tracking system of the present disclosure solves one or more of the problems set forth above.